Hooking Silverlight DatePicker convert from text to DateTime
I want to DatePicker
convert the following text snippets to DateTime
(shown in international format) so that my clients can write the date in the textbox faster DatePicker
, so I won't use DateTime.Parse
:
"3" to 2009-10-03
"14" to 2009-10-14
"1403" to 2009-03-14
"140310" to 2010-03-14
"14032010" to 2010-03-14
I've tried different methods but they don't work. I tried to bind DatePicker.Text
/ DatePicker.SelectedDate
/ DatePicker.DisplayDate
to a custom evaluated converter. But it doesn't work because it DatePicker
has already processed the text before I get the text.
I also tried converting to DatePicker
TextBox.LostFocus
like this:
public class CustomDatePicker : DatePicker
{
private DatePickerTextBox textBox;
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
textBox = this.GetTemplateChild("TextBox") as DatePickerTextBox;
if (textBox != null)
textBox.LostFocus += textBox_LostFocus;
}
void textBox_LostFocus(object sender, RoutedEventArgs e)
{
if (textBox == null) return;
DateTime result;
// This is my method for converting my special cases,
// parses d, dd, mm, ddmm, ddmmyy, ddmmyyyy
if (textBox.Text.TryParseShortcut(out result))
{
// I have also tried with
// this.SelectedDate/DisplayDate = result;
textBox.Text = result.ToString("dd/MM/yyyy");
return;
}
if (DateTime.TryParse(textBox.Text, out result))
{
// I have also tried with
// this.SelectedDate/DisplayDate = result;
textBox.Text = result.ToString("dd/MM/yyyy");
return;
}
}
}
Any ideas?
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If you are using Binding to bind data to your DatePicker, you can use ValueConverter.
A quick example of a date converter:
public class CustomDateValueConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (value is string)
{
string dateValue = (string)value;
switch (dateValue.Length)
{
case 1:
case 2:
return new DateTime(DateTime.Now.Year, DateTime.Now.Month, System.Convert.ToInt32(dateValue)).ToString("dd/MM/yyyy");
//...
}
}
return value;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
// here you should implement your logic to convert your value back.
return value;
}
}
Controlling DatePickerTextBox in XAML:
<controls:DatePickerTextBox Text="{Binding Path=Data, Mode=TwoWay, Converter={StaticResource CustomDateValueConverter}}" />
DatePickerTextBox in cs:
public partial class MainPage : UserControl
{
public MainPage()
{
InitializeComponent();
DataContext = new MyData() { Data = "3" };
_textBox.LostFocus += (se, ea) =>
{
_textBox.DataContext =
new MyData() { Data = _textBox.Text };
};
}
public class MyData
{
public string Data { get; set; }
}
I just created the MyData class to use as data in this example.
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I think you might need to actually run the full control source and configure it. The problem is that the text is updated in the TextChanged event:
private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{
if (this._textBox != null)
{
this.SetValueNoCallback(TextProperty, this._textBox.Text);
}
}
So, by the time you get to your lost focus code, the value is already set. I managed to get around this by subclassing, but since TextChanged handles every change, I'm not sure if your parse method will work (since as soon as you hit 1 number it will be changed to date).
public class CustomDatePicker : DatePicker
{
private TextBox textBox;
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
textBox = this.GetTemplateChild("TextBox") as TextBox;
if (textBox != null)
textBox.TextChanged += textBox_TextChanged;
}
void textBox_TextChanged(object sender, TextChangedEventArgs e)
{
if (textBox.Text == "now")
{
// I have also tried with
// this.SelectedDate/DisplayDate = result;
textBox.Text = DateTime.Now.ToShortDateString();
}
}
}
It works for me since nothing changes until it has spoken all the words, but in your case it probably won't work.
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